The iconic ULA Circuit is famous among thru-hikers for being a lightweight backpack with just enough features to comfortably carry everything you’d need on a long-distance hike. The Ultra 24 Circuit features a serious fabric upgrade that’s even lighter than the original, just as durable, and highly water resistant.
ULA Ultra 24 Circuit
Note: This is a 68L pack. The number "24" is only part of the new series name.
✅ High-load capacity
✅ Very water-resistant
❌ Slightly heavier than other framed packs
- Weight: 34.7 ounces (2 lbs, 2.7 oz)
- Weight/Load Capacity: 35 pounds
- Volume/Carrying Capacity: 68 Liters
- Volume of Main Compartment (not including the extension collar): 40 Liters
- Frame: Carbon fiber and Delrin suspension hoop, foam frame sheet, and aluminum stay
- Frame Material: Carbon Fiber, Delrin, Aluminum
- Suspension System: Padded hip belt with side tensioners and two strap hip belt adjuster, padded straps (J or S-shaped options) with load lifters, moveable sternum strap, 3-D mesh back panel
- Material: Ultra 400 and Ultra 200 (also available in Robic nylon for a lower price and 3 ounces higher weight)
The ULA Ultra 24 Circuit is a new and lighter but just as durable version of the classic ULA Circuit. The Circuit is a thru-hiker favorite. It is lightweight and simple while still being comfortable. And, it will last longer than it takes you to triple crown. The Circuit also has a lifetime warranty, and for the life of the pack, ULA will repair damages due to wear and tear or accidents.
If you’re looking for a pack for thru-hiking or lightweight backpacking, the Circuit is an excellent choice. This pack has been the most popular backpack among Pacific Crest Trail thru-hikers for the past three years, according to Halfway Anywhere’s survey.
With the Ultra 24 Circuit, ULA has shaved weight off their very popular pack down to 2 pounds, 2.7 ounces. They do this by using a combination of Ultra 200 and 400 materials on their pack. Ultra 200/400 material is an Ultra-high-molecular-weight polyethylene (UHMWPE) material that’s stronger than DCF and nearly as light. It is also waterproof, just like DCF. ULA added a much more durable stretch Dyneema outside pocket to their Ultra 24 Catalyst.
The Ultra 24 Circuit is $100 more expensive than the standard Circuit, but the weight savings, durability, and water resistance make it competitive with the most ultralight full-framed packs out there.
For reviews on other ultralight backpacks, read our post on the best ultralight backpacks.
Performance Test Results
What We Tested:
The Ultra 24 Circuit weighs 34.7 ounces, which is lighter than most full-framed backpacks. While this isn’t the most lightweight backpack with a frame available, it is close to the lightest you can get. The Ultra 200 and 400 materials used in this pack are lighter than the standard ULA circuit, which is made with Robic material and weighs 37.3.
I found this pack is weighted well considering its specs and features. There is nothing extra on this pack that isn’t worth the weight. You can also remove the frame and hip belt, making the pack weigh under 2 pounds. However, I think the frame and hipbelt are worth the weight.
With everything included in this pack, it weighs 34.7 ounces. Fully stripped, it weighs 25.6 ounces. You can remove the frame (1.2 ounces), hip belt (7.3 ounces), and rear shock cord (0.6 ounces) of this pack. If you want to cut straps off this pack, you can strip even more weight, but I don’t recommend this.
Overall, this pack provides an excellent value for the price. The Ultra 24 version is slightly more expensive than other similar packs, but it comes with hip belt pockets, a full suspension frame system, Dyneema mesh outside pocket, and tension adjustable water bottle pockets. It costs $25-50 more than other packs that weigh a similar amount and have a frame. However, this pack carries weight well, uses the most durable materials, and is the most full-featured pack I have found in the 30-35 ounce weight range.
The Robic version of this pack is $100 less expensive than the Ultra 24 version I tested. If you’re on a budget, the Robic Circuit is an excellent deal for a great pack with all the same features as the Ultra 24 Circuit I’m reviewing here.
The premium fabrics used in constructing this pack are the reason for the high price. I think the Ultra material is a great pack material, but so is the Robic material used in the less expensive Circuit. If 3 ounces of weight savings is worth a hundred dollars to you, the Ultra 24 is a great choice.
The Ultra 24 Circuit comes with stretch Dyneema material for the outer pocket. This stretch Dyneema material is the most durable back pocket material I’ve ever used and therefore very worth the price. I had this same stretch Dyneema material on my pack when I thru-hiked the CDT, and it went the entire 3,000-mile hike without getting a single hole.
While the Ultra 24 Circuit isn’t cheap, it’s not much more expensive than other ultralight packs. The stretch Dyneema pocket, Ultra 200 and 400 fabric, hip belt pockets, and load lifters are more features than what comes on this pack’s competitors. All of these features are worth it, too. They each contribute a great deal to the pack’s overall performance.
Storage and Capacity: 9/10
This pack has a weight capacity of 35 pounds and can carry a typical lightweight backpacker or thru-hiker’s gear. If your base weight is below 15 pounds, you have enough weight capacity to carry about 20 pounds worth of food and water on top of your base weight. The main compartment is big enough to carry a full-size bear canister vertically, too.
I found this pack has the right amount of space for a thru-hike. The main compartment on this pack is 40 liters if you roll it down entirely. If you don’t roll it down to the frame, the main compartment is closer to 45 liters. It also has two side pockets. Each pocket will hold two Smartwater bottles. The pack’s Dyneema mesh front pocket will stretch to fit a jacket, snacks, and other items you want to access quickly.
The weight-to-volume ratio of this pack is good, too. The Ultra 24 Circuit weighs less than most other packs that are similarly sized, and it carries weight just as well as packs that weigh more than it. The hip belt also has pockets, which are big enough for a smartphone or a few bars. Many ultralight framed packs don’t come standard with hip belt pockets, either.
Internal Frame: 9/10
Overall, I found the Circuit’s frame provides excellent support and load-carrying abilities. It has a similar frame design to many other ultralight models, but it’s available in two shoulder strap shape options to fit a wider variety of women’s and men’s bodies.
The internal frame transfers the pack weight in the shoulder straps to the hip belt. The Circuit’s frame consists of a Carbon fiber and Delrin hoop, a vertical aluminum strut, and a foam back panel. The hoop makes an upside-down U shape, anchoring to each side of the hip belt and looping across the shoulders, attaching to each shoulder strap. The aluminum strut also helps transfer weight to the hip belt in conjunction with the Carbon and Delrin hoop.
The entire suspension system of the Circuit consists of the frame, hip belt, and shoulder straps. The shoulder straps have load lifters, which allow you to control how much weight is on those straps. Each side of the hip belt also has a tension adjuster, much like shoulder strap load lifters but for adjusting the hip belt load. These hip belt load lifters control how much the pack hugs your hips and prevents it from swaying as you move as well.
The Circuit comes with two shoulder strap shape options: J or S-shaped. J-shaped straps typically are the most comfortable for men, while S-shaped straps are more comfortable for a typical woman’s shoulders. However, many men also prefer S-shaped straps. I’m a man, and the Circuit I tested has S-straps. Personally, I find the S-shape to very comfortably wrap around my shoulders.
If you unclip the hip belt, all the weight in the pack will be on the shoulders. This can be very uncomfortable on some packs, but with the Circuit, it isn’t that bad. Likewise, by loosening the load lifters all the way you can see how comfortable the hip belt is on its own. Well, the hip belt is also very comfortable. When removing the hip belt, I noticed it has a gentle curve–nothing too crazy, just enough to follow the contours of the hips.
The Circuit is very comfortable, thanks to the 3-D mesh on the back panel and insides of the shoulder straps and hip belt. The 3-D mesh does not chaff when wearing the pack for long periods, and it allows air to flow between the pack and your body. The shoulder straps have a good amount of padding, and it’s dense enough to not compress quickly while still being comfortable.
The frame and suspension system makes it easy to distribute the load onto different areas of your body. This also makes the pack more comfortable since you can give your shoulders a break by transferring the bulk of the load to the hips or vice versa.
This pack is extremely comfortable compared to the other ultralight packs. This is the only ultralight pack with a full 3-D mesh back panel. The 3-D mesh along your back is much more comfortable than the not-at-all-breathable ultralight materials used on the back of most ultralight packs.
This pack has the right features that improve its functionality without unnecessarily adding weight. The Circuit has the following features:
- Full frame to distribute weight between shoulders, back, and hips
- Padded hip belt with four adjusters for the main buckle to get ideal hip belt fit
- Hip belt side compression adjusters to pull load closer to your body
- Hip belt pockets to stash small items to be accessed quickly
- 3-D mesh on the back panel, the interior of the shoulder straps, and inner hip belt to make touch points more comfortable and breathable
- Stretch Dyneema mesh exterior front pocket for stashing gear on the outside of the pack
- Load lifters to adjust the weight on your shoulders
- Shoulder straps are available in J-shape and S-shape to fit women’s and men’s anatomy
- Roll top that secures with side compression straps to fully compress the pack from the top
- Another center buckle strap for attaching gear to the top of the pack
- Side pack compression straps to compress the pack load laterally
- Adjustable water bottle side pockets can be tightened or loosened depending on the size of your bottle(s)
- Dual ice axe or trekking pole carrying loops
- Removable front shock cord for attaching gear to the outside of front mesh pocket, to dry a jacket or other gear items
The Circuit has more features than any other ultralight pack I’ve found. Though it is a few ounces heavier than similar ultralight packs, the Circuit has more features. I think it’s worth the extra ounces for such a long list of great features.
The Circuit is about as adjustable as most other ultralight packs on the market. It is adjustable by weight, volume, and many elements of sizing.
You can remove the hip belt, frame, and rear shock cord on the Circuit to adjust the weight. This would drop the weight from 34.7 to 25.6 ounces.
You can also adjust the pack's volume by rolling down the main compartment. When rolled down all the way, the main compartment is 40 liters. When packed to capacity it is 48 liters.
The hipbelt has about 5 inches of adjustability and has a dual strap adjustment system to dial in the fit around your hips. The hip belt comes in 6 different sizes:
- X-Small (26”-30” waist)
- Small (30”-34”)
- Medium (34”-38”)
- Large (38”-42”)
- X-Large (42”-47”)
- XX-Large (47”+)
You can remove and reinstall a different size hipbelt if you gain or lose weight.
Each torso size of this pack is adjustable by 4 inches via the shoulder straps:
- Small (15”-18” torso)
- Medium (18-21”)
- Large (21”-24”)
- X-Large (24”+)
As I mentioned above, you also have two options for shoulder strap shape when ordering the pack: J or S-shaped.
The material used in the Ultra 24 Circuit is waterproof. However, the pack does not have taped seams, so it is not fully waterproof where the fabric has been sewn. I would call this a very water-resistant pack but would definitely still use a pack liner with it.
This pack is about as waterproof as other ultralight packs that do not come with taped seams. Some ultralight packs come fully seam-taped, and the Ultra 24 Circuit is not as waterproof as those.
ULA has been resistant to using Dyneema Composite Fiber to make their packs for years because it doesn’t meet their durability standards. With the Ultra 24 Circuit, they have finally made a pack with lighter weight materials than their traditional Robic “gridstop” nylon. The Ultra 24 Circuit still comes with ULA’s lifetime warranty, which says a lot about how durable Ultra 200 and 400 are.
After extensive testing, the Ultra 24 Circuit has no obvious wear marks or tears. I spent weeks wearing this pack stuffed full of gear, loading it and unloading it again and again, and generally abusing it. It shows no substantial signs of wear.
ULA is the only ultralight pack maker that offers a lifetime warranty. They’ve been making packs for over 20 years and haven’t gone out of business from giving away packs that fail. That’s because these packs don’t fail. If any of their packs get damaged, ULA will repair them, too.
I’ve seen 1000s of ULA packs last multiple thru-hikes. Most triple crowners who started their 8000+ miles of backpacking with a Circuit end with that same pack. This can’t be said for most other ultralight packs.